Nanotechnology Health and Environmental Risks - Chapter 7 pot

113 7 Alternative Approaches for Life Cycle Risk Assessment for Nanotechnology and Comprehensive Environmental Assessment Jo Anne Shatkin and J. Michael Davis A number of parties have converged on the idea of integrating life cycle thinking and risk analysis as a path forward for evaluating nanotechnol- ogy risks. Several alternative frameworks have been proposed, and it is clear that life cycle thinking is an important attribute of substance and technology management amid uncertainty. Broadly considered, there is nothing specic to nanotechnology about the frameworks discussed in this chapter. Simply, they represent current thinking and may become broadly applicable for nanotechnology because no existing frameworks are ade- quate to address the breadth of concerns about impacts on health and the environment. Analyzing and managing risks from materials, products, and technology across the life cycle represents a novel approach to sustainable materials development. Under the Toxic Substances Control Act, submitters of new substances must make preliminary assessments of the potential for persis- tence and bioaccumulation, along with other chemical property data, to look for early indications of persistent, bioaccumulative, and toxic compounds. CONTENTS 7.1 Adopting a Life Cycle Approach to Risk Analysis 114 7.2 Society for Risk Analysis Symposium on Life Cycle Approaches to Risk Assessment of Nanoscale Materials 115 7.3 Perspective on the SRA Symposium and Alternative Frameworks 117 7.4 Comprehensive Environmental Assessment 120 7.4.1 Features of Comprehensive Environmental Assessment 121 7.4.2 Illustration of CEA Applied to Selected Nanomaterials 122 7.5 Summary 125 References 126 53639.indb 113 3/28/08 2:32:39 PM © 2008 by Taylor & Francis Group, LLC 114 Nanotechnology: Health and Environmental Risks Under REACH companies must consider exposure scenarios for workers, consumers, and the environment. However, the approaches described here and in Chapter 6 incorporate life cycle thinking more broadly and explic- itly. A necessary step is public vetting of the various frameworks and their implications, requiring broad participation in establishing how to adopt a life cycle risk assessment approach for nanomaterials and nanotechnology risk management. 7.1 Adopting a Life Cycle Approach to Risk Analysis The idea behind this book originated in 2005, with Shatkin’s work on the NANO LCRA framework, described in Chapter 6. That is, while the data needed for quantitative risk assessment are not yet available, the need for risk assessment is great, requiring an approach to evaluate what is known, and what needs to be known, to make decisions about how to manage the risks, prior to having data available to quantify them. Experience shows that “back of the envelope” or screening-level evaluation is a valid step before embarking on complex and detailed assessments. Although it is difcult to pinpoint exactly where and when the idea to integrate LCA and RA rst arose, an early focal point was the 2000 Society for Risk Analysis (SRA) Annual Meeting in Washington, DC. The meeting became the backdrop for interdisciplinary discussions between life cycle analysts and risk assessors to discuss common themes (Evans et al. 2002). This led to a series of papers published in the journal Risk Analysis (Volume 22 (5) 2002). There have been broad calls for adopting a life cycle approach to nanotech- nology (COM 2004; Sweet and Strom 2006; EPA 2007; Sass 2007). Shatkin rst introduced the NANO LCRA framework for nanotechnology at the Foresight Institute Nanotechnology Conference, “Advancing Benecial Nanotechnol- ogy,” in October 2005 (Shatkin 2005), and later at the NSTI Nanotech 2006 meeting in Boston (Shatkin and Barry 2006), among other forums. At NSTI, three other presentations also described life cycle approaches to risk analy- sis for nanotechnology. At that time, Davis was developing a manuscript on comprehensive environmental assessment for nanotechnology (Davis 2007). The seemingly independent developments on LCA and RA spurred us to organize a symposium at the 2006 SRA Annual Meeting in Baltimore, to discuss the alternative frameworks and their applicability to nanotech- nology. The broad and convergent interest in this approach suggests a cor- relative need to evaluate these and other frameworks to understand how to integrate life cycle thinking in a risk assessment. The frameworks them- selves require research, evaluation, and public discussion and debate over 53639.indb 114 3/28/08 2:32:39 PM © 2008 by Taylor & Francis Group, LLC Alternative Approaches for Life Cycle Risk Assessment 115 their implementation. The following is a brief summary of the life cycle risk frameworks presented there. 7.2 Society for Risk Analysis Symposium on Life Cycle Approaches to Risk Assessment of Nanoscale Materials The SRA symposium was a forum to discuss alternative frameworks, the roles they might play in risk management of nanomaterials and nanotech- nology, opportunities and research needs for their development as policy tools, as well as potential consequences of their introduction in voluntary and regulatory decision making processes. Building on the body of work developed at the 2000 SRA Annual Meeting, the symposium included invited presentations of recently proposed life cycle/risk assessment frameworks for nanotechnology under development across diverse organizations represent- ing government, academia, legal, and risk/policy entities, and a collaborative chemical industry/NGO team. At a round table discussion following the presentations, speakers discussed ways in which a life cycle/risk assessment framework could inform risk management and regulatory decision making and the steps necessary for implementing such an approach. J. Michael Davis, Senior Science Advisor from the National Center for Expo- sure Assessment at the U.S. Environmental Protection Agency, described his proposed Comprehensive Environmental Assessment (CEA) Framework that incorporates life cycle thinking into a risk analysis framework. Olivier Jolliet of the University of Michigan described a life cycle framework for nanomaterials that evaluates health and environmental risk. James Votaw of the legal rm Wilmer, Cutler, Pickering, Hale, and Dorr discussed life cycle thinking for legal decision making. Environmental Defense (ED) and DuPont described their joint framework, and Shatkin presented an adap- tive risk assessment framework for management of poorly dened materials intended to identify and prioritize research. Davis described CEA, a framework that combines the risk assessment paradigm with a product life cycle framework. The CEA approach expands on the exposure component of risk characterization (discussed in Chapter 2) by considering life cycle stages, environmental pathways, and transport and fate processes throughout product life cycle, comprising feedstocks, manufacturing, distribution, storage, use, and disposal (including reuse if applicable). Exposure is partly a reection of product life cycle, transport and transformation, and exposure media, but goes beyond characterizing the occurrence of contaminants in the environment. Exposure implies actual contact between a contaminant and organisms, regardless of whether the receptors are biota or human populations. Among the many aspects of expo- sure characterization are routes of exposure (such as inhalation, ingestion, 53639.indb 115 3/28/08 2:32:39 PM © 2008 by Taylor & Francis Group, LLC 116 Nanotechnology: Health and Environmental Risks and dermal absorption), aggregate exposure across routes (the multiple pathways and sources), cumulative exposure to multiple contaminants, and various spatiotemporal dimensions (e.g., people’s activity patterns, diurnal and seasonal changes). These are linked with ecological and human health effects, which can encompass both qualitative hazards and quantitative exposure-response relationships. Also important are considerations such as analytical and measurement methods and control technologies. CEA is described in more detail in section 7.4. Jolliet, one of the key developers of Life Cycle Impact Analysis through SETAC, discussed life cycle risks and impacts of nanotechnologies. Jolliet’s framework adopts a life cycle perspective to analyze the trade-offs between risks and benets of nanotechnologies, as a replacement for conventional technologies, focusing on the impacts on human health. A matrix approach is used to identify risks associated with nanotechnologies over the whole product life cycle (raw material extraction, manufacturing, use phase, dis- posal, and recycling). It looks at (a) the additional risks and benets directly due to nanotechnologies, and (b) the indirect risks and impacts of nanotech- nologies compared to (c) those avoided with conventional technologies, and identies inuence factors. A comparative risk model combines a multimedia model with pharmacokinetic modeling of nanoparticles, to analyze different nano-applications. Votaw, a legal scholar, described an approach, “applying general ‘life cycle assessment’ concepts, … to identifying where the risks lie for a particular organization, and a practical approach to developing a legal risk manage- ment strategy for navigating these uncertainties until the potential environ- mental, health and safety risks, and related regulatory and business risks, are better understood” (Votaw 2006). The SRA Symposium also included a presentation about the draft Environ- mental Defense DuPont “Nano Risk Framework.” The ED DuPont framework is intended to help organize what is known; assess, prioritize, and address data needs; and communicate how risks are managed (ED DuPont 2007). ED and DuPont’s framework is intended to be comprehensive. The framework is information driven, and considers product life cycle. The terms are different from CEA, but the life cycle stages are similar: material sources, production, use, and end-of-life disposal/recycling. A key feature is the development of base data sets at the outset. Five steps are outlined that include: (1) describing the material and its application; (2) proling the material life cycle in terms of properties, potential safety, health, and environmental hazards, and oppor- tunities for human or environmental exposure at each step of the product lifecycle; (3) evaluating risks, either with available data or by assuming the “reasonable worst case;” (4) assessing risk management options, including engineering controls, protective equipment, risk communications, and pro- cess or product modication; and (5) decide, document, and act (ED DuPont 2007). At SRA, Shatkin presented the NANO LCRA framework and its appli- cation to two case studies described in Chapter 6. The following is an 53639.indb 116 3/28/08 2:32:39 PM © 2008 by Taylor & Francis Group, LLC Alternative Approaches for Life Cycle Risk Assessment 117 overview of Shatkin’s SRA presentation. Each word of the adaptive screen- ing level life cycle risk framework conveys meaning. Adaptive means this approach utilizes adaptive management. Adaptive management is important when making decisions under uncertainty. The assumptions and decisions need to be revisited, particularly when new information becomes avail- able. The framework uses a screening-level approach to inform decision making. It does not necessarily complete entire quantitative risk assess- ments at each step, an important aspect distinguishing this framework from others that have been proposed. Risk assessment means taking a step- wise approach, looking rst at the potential hazards, then the potential exposure at each step of the life cycle. After this level of analysis, the need for information about toxicology can be considerably narrowed to the key pathways leading to human and ecological exposure, and information obtained about the specic health effects associated with these exposures. The available information is used to conduct an assessment, which may or may not be quantitative. Preliminary decisions can be made at this step about the immediacy of need for additional data, how to protect workers, and whether and what types of steps should be taken to protect product users and the environment. 7.3 Perspective on the SRA Symposium and Alternative Frameworks Both the NANO LCRA and CEA frameworks focus on exposure assessment before considering the toxicology of nanomaterials, and both seek a trans- parent assessment process. The main differences between the frameworks proposed by Davis and Shatkin are that Shatkin focuses on a screening-level assessment that builds to greater levels of detail, for risk management deci- sions, using adaptive management. CEA is a risk assessment methodology that can also be qualitative and incorporate adaptive features and, because of its interdisciplinary nature, incorporates the collective judgment of a range of experts. Jolliet offered that industrial ecologists begin with a different frame in mind. They tend to focus on a broad range of outputs related to the use of water, energy, contribution to climate change, and impacts on eco- systems (such as eutrophication) in addition to toxicity, which focuses on cancer and non-cancer effects. The units of analysis, whether per mass of material or on the basis of annual use, affect the resulting rankings. ED and DuPont’s joint framework is intended to be comprehensive. A key feature is the development of base data sets at the outset. Both Jolliet and ED DuPont approaches rely on signicant data collection and analysis. CEA intends to be comprehensive without necessarily conducting all necessary research 53639.indb 117 3/28/08 2:32:39 PM © 2008 by Taylor & Francis Group, LLC 118 Nanotechnology: Health and Environmental Risks upfront. NANO LCRA incorporates modeling and bounding analysis to characterize impacts. The SRA symposium raised many good questions about how to incorpo- rate life cycle thinking into risk analysis. An issue that arose in the SRA Symposium is that how one frames the problem determines the results of the process. The life cycle assessment process can compare risks across two different materials in units of health, environment, or energy, and how this is done can affect the results. For example, when in the life cycle of a nanomaterial is there potential for exposure to nanoscale particles? Again, how the problem is formulated affects the results. Regulators and other risk managers have not typically made risk management decisions based on the life cycle of a material — although increasingly they are considering the potential for substances to be persistent and bioaccumulative. Regula- tions typically involve decisions about a substance in a specic context, i.e., in drinking water, or a microbe in a food product or process. There is a need to evaluate how to accomplish the task of being comprehensive in assessing the risks of a substance or product, and to address what its meaning is in a risk management context. Some issues arise with the ED DuPont nano risk framework. The rst is that the framework as proposed requires such signicant effort, it is dif- cult to imagine anyone except an organization with the resources of DuPont implementing it. For example, the ED DuPont framework includes evaluation of the risks at each stage of the life cycle for all products associated with a nanomaterial, across the entire supply chain. This suggests a complex, inves- tigational approach for managing risks under uncertainty, in the absence of regulation. The framework also requires a signicant level of expertise in many different elds. One could envision an engineer without training in toxicology or environmental science might try to do the evaluations and reach wrong conclusions about an environmental fate evaluation or the sig- nicance of a toxicology study. The ED DuPont framework requires a lot of upfront analysis in developing the base data sets, suggesting it may take a signicant level of effort to develop the data for the analysis. It is unclear how these data relate to product development. An interesting phenomenon happened after ED and DuPont released their draft framework for public comment in February 2007. In response, a group of about 20 non-governmental, public interest, and labor organizations published a letter responding to the framework, saying that because it was developed privately, it was invalid, and they would not acknowledge it by commenting on it. A coalition of non-governmental organizations, includ- ing the AFL-CIO, United Steelworkers of America, Friends of the Earth, Greenpeace, the International Center for Technology Assessment, and the Natural Resources Defense Council (NRDC) wrote an “Open Letter to the International Nanotechnology Community at Large,” urging all to reject the “public relations campaign” (Coalition Letter 2007). In a press release, the coalition expressed concerns about the lack of broad participation in the framework development: “We strongly object to any process in which broad 53639.indb 118 3/28/08 2:32:40 PM © 2008 by Taylor & Francis Group, LLC Alternative Approaches for Life Cycle Risk Assessment 119 public participation in government oversight of nanotech policy is usurped by industry and its allies” (Coalition Letter 2007). The coalition denounced the framework as “fundamentally awed” because it was developed by industry and their allies without government oversight or public involve- ment. Their key concern was that the framework could become a voluntary approach, which could delay legislation and forestall public involvement. Shortly thereafter, NRDC produced their own analysis recommending a life cycle approach to evaluating the risks from nanotechnology (Sass 2007). At the June 2007 public release of the framework, ED and DuPont presented a somewhat revised framework, concluding that in some situations, it was unrealistic to be quantitative and that one does not necessarily want to col- lect data in some situations. In fact, using the framework led to a decision by ED and DuPont not to go forward with an evaluation of one material because they could not obtain the base set of data (nanoriskframework.com). Perhaps by the time you are reading this, another forum for public dis- cussion of the various frameworks and how a life cycle approach to risk analysis could be adopted either on a voluntary or a regulatory basis will occur. Developing a new approach to managing the risks of new substances requires signicant discussion and communication. Therefore, it is disap- pointing to see the negative reaction to the ED DuPont framework, which said that “the DuPont-ED proposal is, at best, a public relations campaign that detracts from urgent worldwide oversight priorities for nanotechnol- ogy…” (Coalition Letter 2007). An alternative view is that these two orga- nizations used their collective extensive resources to dene for them what information is needed to make sound decisions for managing nanotechnol- ogy risks in the absence of regulation. It is to their credit that ED and DuPont put up their own resources and put the framework in the public domain for debate, discussion, and potential adoption. The positions of some non-governmental organizations regarding nano- technology raise serious concerns about the potential for using a science- informed approach in environmental decision making. If there were a clear path to regulation, and it were clear that regulating nanotechnology now would improve public health and the environment, governmental col- leagues in a regulatory role would be working diligently toward this end. In fact, many health and environmental organizations with regulatory responsibilities have reported on internal evaluations regarding whether the new regulations are needed for nanotechnology (EC 2007; EPA 2007; FDA 2007; Environment Canada 2007). If new regulations are necessary, the rule-making process generally requires years of development. In the interim, it is imperative to be managing risks, and voluntary approaches are an important step toward that management. It is greatly hoped that some integration of the frameworks discussed here will occur, which can be adopted as tools for transparent evaluations of nanomaterials and nanotechnologies by developers, users, and risk managers in the public and private sectors, and that these evaluations can inform science-based 53639.indb 119 3/28/08 2:32:40 PM © 2008 by Taylor & Francis Group, LLC 120 Nanotechnology: Health and Environmental Risks sustainable technology development and management. In the next section, CEA is discussed in detail. 7.4 Comprehensive Environmental Assessment The idea of Comprehensive Environmental Assessment (CEA) was rst developed in reference to fuels and fuel additives (Davis and Thomas 2006), although its applicability to other technological issues, including nanotech- nology, has been apparent (Davis 2007). Its origins in relation to fuels/fuel additives (F/FAs) owes a great deal to the Alternative Fuels Research Strat- egy (U.S. EPA 1992) that was developed by the EPA’s Ofce of Research and Development to lay out a framework for assessing the benets and risks of various F/FAs. In essence, both the Alternative Fuels Research Strategy and the CEA approach combine a life cycle perspective with the risk assessment paradigm (described in the following). The advantage of a life cycle perspective is that it allows a broader, more systematic examination of the trade-offs associated with a product. This point is well-illustrated by the case of methyl tertiary butyl ether (MTBE), a fuel additive that has been widely used to increase the oxygen content and octane number of gasoline. As discussed in Chapter 3, during the 1990s, MTBE use grew dramatically in the United States mainly in response to pro- visions in the 1990 Clean Air Act Amendments that called for the use of oxy- genates in gasoline to address certain air quality problems. Although MTBE was at one time used in approximately one third of U.S. gasoline, its use declined precipitously because of concerns about its potential to contaminate water resources when leaking from underground fuel storage tanks (USEPH 1998; USEPH 1999). Thus, a product that was intended to improve air quality ended up being unacceptable due to water contamination issues. The Alternative Fuels Research Strategy (U.S. EPA 1992) presciently warned about potential problems with MTBE (and a related oxygenate, ethyl tertiary butyl ether [ETBE]) when it stated: “Compared to gasoline, the ethers MTBE and ETBE have relatively large aqueous solubilities and would likely leach more rapidly through soil and groundwater. Also, limited data suggest that ethers may be persistent in subsurface environments.” And, “Very little is known about emissions and releases from MTBE and ETBE storage and distribution, making this area an appropriate target for research. Effects on existing equipment and controls…need to be evaluated” (U.S. EPA 1992). As it turned out, the propensity of MTBE in gasoline to leak from under- ground fuel storage tanks and thus foul groundwater proved to be the Achil- les heel of this product. But correctly anticipating this problem was not a uke or coincidence; rather, it was the result of a collective effort by EPA scientists to think through various implications of MTBE and other F/FAs in relation to the entire life cycle of the fuels, not just their intended end use. 53639.indb 120 3/28/08 2:32:40 PM © 2008 by Taylor & Francis Group, LLC Alternative Approaches for Life Cycle Risk Assessment 121 The CEA concept extends and formalizes the approach that was used in the Alternative Fuels Research Strategy. 7.4.1 Features of Comprehensive Environmental Assessment The CEA approach, shown in Figure 7.1, is an expansion of the basic risk assessment paradigm. It encompasses identication of both human health hazards and ecological stressors, but it also elaborates the exposure compo- nent of risk characterization. First, various stages of the product life cycle are considered. Typically this would include feedstocks, manufacturing, distribution, storage, use, and disposal/recycling. At each of these stages some potential may exist for releases/emissions of materials into the vari- ous environmental media (air, water, soil, and food web). Of interest here are the primary materials as well as by-products such as manufacturing waste. Both primary and secondary contaminants may undergo transport and transformation processes, which in turn may yield additional by-products. Aggregate and cumulative exposure of biota and human populations would thus potentially involve multiple environmental media and pathways, with multiple routes of exposure to not only the primary material but secondary by-products. Adequate empirical data may not exist for such complex characterizations of exposure. Again, as with the NANO LCRA framework, in lieu of quantitative information, the CEA approach relies on qualitative characterization. Indeed, the use of qualitative information distinguishes CEA from the much more quan- titative analyses generally employed in life cycle assessment (LCA) and life cycle impact assessment (LCIA). Thus, even if numeric estimates of material FIGURE 7.1 Comprehensive environmental assessment framework. (Adapted from Davis 2007). (See color insert following page 76.) 53639.indb 121 3/28/08 2:32:41 PM © 2008 by Taylor & Francis Group, LLC 122 Nanotechnology: Health and Environmental Risks releases/emissions are unavailable, it should be possible to describe such contamination in qualitative terms. The importance of doing this is illustrated by the statements about MTBE quoted from the Alternative Fuels Research Strategy (EPA 1992). Even though no quantitative estimate of the likelihood of MTBE leakage and water con- tamination was feasible at that time, the qualitative potential was at least a warning signal that could have resulted in closer monitoring, better control technology, or other steps that could have mitigated the problem of water contamination. The fact that such preventive actions did not occur is not an indictment of the ability to anticipate potential problems, as much as a lesson to risk managers to heed the insights of technical experts in their attempt to think through the environmental implications of a new technology. Reliance on collective judgment is another distinguishing feature of the CEA approach. Given the complexity and lack of data on the health and environ- mental implications of nanomaterials, it is clear that no single individual or even small group of persons can have the breadth of knowledge needed to consider the many facets of a CEA of nanomaterials. Instead, an array of technical experts and stakeholders is needed to support a CEA. It is also important that the knowledge and judgments of these individuals be tapped in a structured manner. A “free for all” discussion does not provide as much benet as formal, controlled discussions under the leadership of trained facilitators using techniques such as expert elicitation and multi-criteria decision analysis. 7.4.2 Illustration of CEA Applied to Selected Nanomaterials The importance of the product life cycle is quickly evident in considering the potential impacts of a nanomaterial such as titanium dioxide (TiO 2 ), which is used in numerous applications ranging from coatings to water treatment agents and in closed industrial settings to general consumer products. The opportunities for exposure to TiO 2 are likely to be quite different, depending on whether or not the substance is tightly bound in a matrix. For example, TiO 2 used in light-emitting diodes would appear to pose less potential for dispersion in the environment than TiO 2 used as a water treatment agent. As a water treatment agent, there could be several opportunities for a powder of nanoscale particles to be released to the environment subsequent to manufac- turing, including spillage during distribution, storage, and use. In addition, differences in manufacturing processes have been found to yield different physical and even toxicological properties of nominally equivalent nanoma- terials (Dreher 2004). Thus, to evaluate the full range of potential ecological and health impacts associated with any given nanomaterial, it is necessary to consider the broader life cycle context for the material in question. Using water treatment applications of nanoscale TiO 2 as an example, the product life cycle begins with the feedstocks from which the material is pro- duced. Either titanium chloride or titanium sulfate can serve as feedstocks for producing nano-TiO 2 , with the possibility of some contamination of the 53639.indb 122 3/28/08 2:32:41 PM © 2008 by Taylor & Francis Group, LLC [...]... http://www.aerosil com/ Accessed 1/ 07/ 07 Dreher, K 2004 Health and environmental impact of nanotechnology: Toxicological assessment of manufactured nanoparticles Toxicol Sci 77 : 3-5 EC 20 07 Nanosciences and Nanotechnologies: An action plan for Europe 200 5-2 009 First Implementation Report 200 5-2 0 07 COMMUNICATION FROM THE COMMISSION TO THE COUNCIL, THE EUROPEAN PARLIAMENT AND THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE... europa.eu /nanotechnology/ actionplan.htm Davis, J M and V M Thomas 2006 Systematic Approach to Evaluating Trade-Offs among Fuel Options The Lessons of MTBE Ann N.Y Acad Sci 1 076 : 49 8-5 15 Davis, J M 20 07 How to assess the risks of nanotechnology: learning from past exprience J Nanosci Nanotech 7: 40 2-4 09 Davis, J M., and W H Farland 20 07 The paradoxes of MTBE Toxicol Sci 61:211–2 17 Degussa 20 07 Technical Specifications for... 25(4):1132–11 37 Oberdörster, G., J Ferin, and B E Lehner 1994 Correlation between particle size, in vivo particle persistence, and lung injury Environ Health Perspect 102(6): 17 3-1 79 Rincon, A G., and C Pulgarin 2003 Photocatalytic inactivation of E coli: Effect of (continuous-intermittent) light intensity and of (suspended-fixed) TiO2 concentration Appl Catalyis B-Environ 44:26 3-2 84 Sass, J May 20 07 NRDC... Y Chen, and J C Crittenden 20 07 Enhanced accumulation of arsenate in carp in the presence of titanium dioxide nanoparticles Water Air Soil Pollut 178 :245–254 © 2008 by Taylor & Francis Group, LLC 53639.indb 1 27 3/28/08 2:32:42 PM 128 Nanotechnology: Health and Environmental Risks Sweet, L., and Strohm, B June 2006 Nanotechnology — life-cycle risk management Human Ecol Risk Assess 12(3):52 8-5 51 U.S.EPA... consumer/fuels/oxypanel/r99021.pdf Accessed March 9, 20 07 U.S EPA 20 07 Final Nanotechnology White Paper EPA 100/B- 07/ 001 http://www epa.gov/OSA/pdfs/nanotech/epa -nanotechnology- whitepaper-02 07. pdf Accessed February 28, 20 07 Votow, J G 2006 Navigating the uncertainties: Nanotech EHs legal risk management Strategies Symposium on analyzing nanotechnology risks across the life cycle: Strategies and policy implications Society for Risk... used for decision making and risk management under uncertainty This chapter broadly considered risks from occupational and environmental exposures In the remaining chapters we explore the current state of practice and international efforts to address occupational and environmental risks issues References Bermudez, E., J B Mangum, B A Wong, B Asgharian, P M Hext, D B Warheit, and J I Everitt February... mice, rats, and hamsters to subchronic inhalation of ultrafine titanium dioxide particles Toxicol Sci 77 (2):34 7- 5 7 Bermudez, E., J B Mangum, B Asgharian, B A Wong, E E Reverdy, D B Janszen, P M Hext, D B Warheit, and J I Everitt November 2002 Long-term pulmonary responses of three laboratory rodent species to subchronic inhalation of pigmentary titanium dioxide particles Toxicol Sci 70 (1):8 6-9 7 Coalition... Environ Health A(65):151 3-1 503 Kuhn, K P., I F Chaberny, K Massholder, M Stickler, V W Benz, H G Sonntag, and L Erdinger 2003 Disinfection of surfaces by photocatalytic oxidation with titanium dioxide and UVA light Chemosphere 53(1): 7 1 -7 7 Long, T C., J Tajuba, P Sama, P Gillespie, N Saleh, J Parker, C Swartz, and B Veronisi 20 07 Nanosize TiO2 stimulates reactive oxygen species in brain microglia and damages... (Chemicals and Polymers) http://www.ec.gc.ca/substances/nsb/ pdf/a20 070 6_e.pdf Accessed July 20, 20 07 Evans, J S., P Hofstetter, T E McKone, J K Hammitt, and R Lofstedt 2002 Introduction to Special Issue on Life Cycle Assessment and Risk Analysis Risk Analysis 22(5):819–820 FDA 20 07 Nanotechnology A Report of the U.S Food and Drug Administration Nanotechnology Task Force http://www.fda.gov /nanotechnology/ taskforce/... AP-92.002 http://www.epa.gov/ncea/pdfs/mtbe/altfuel.pdf U.S EPA 1998 Research Strategy for Oxygenates in Water Federal Register: February 23, 1999 (Volume 64, Number 35) Page 88 17 FRL-623 4 -7 U.S EPA.1999 Achieving Clean Air and Clean Water: The Report of the Blue Ribbon Panel on Oxygenates in Gasoline EPA420-R-9 9-0 21 http://www.epa.gov/otaq/ consumer/fuels/oxypanel/r99021.pdf Accessed March 9, 2007 . March 9, 20 07. U.S. EPA. 20 07. Final Nanotechnology White Paper. EPA 100/B- 07/ 001. http://www. epa.gov/OSA/pdfs/nanotech/epa -nanotechnology- whitepaper-02 07. pdf. Accessed February 28, 20 07. Votow,. nanoparticles. Toxicol. Sci. 77 : 3-5 . EC 20 07. Nanosciences and Nanotechnologies: An action plan for Europe 200 5-2 009. First Implementation Report 200 5-2 0 07 COMMUNICATION FROM THE COM- MISSION TO THE COUNCIL,. nanoscale mate- rials. NSTI-Nanotech 20 07. Proceedings (1):55 3-5 57. www.nsti.org. Shatkin, J. A. 2006. Symposium T-3A. Analyzing nanotechnology risks across the life cycle. Strategies and policy